An excellent way to expand your knowledge of the fretboard is to learn how to play scales on only one string. Instead of using an up-and-down vertical approach, linear one-string licks can have numerous benefits. For playing fast runs, it’s relatively easy to do this on one string. Also, for more melodic soloing, staying on one string and sliding between notes can be very expressive. One of the main advantages of one-string playing is that once you know a scale in a particular key, you can fairly easily transpose it to a different key or another string – the arrangement of notes will stay the same and all you have to do is change the root note. A really good exercise is to limit yourself to using only one string during a solo improvisation, since it forces you to come up with new ideas that you may not have thought of otherwise

The following one string exercises use a different lick on each of the six strings, in a different key, and using a different scale. The choice of scales used is quite deliberate – five of them are minor key scales containing a minor third (Natural minor, Harmonic minor, Dorian, Phrigian, Locrian). These are all very commonly used in heavy metal, which is predominantly minor key-based. The exception is the last exercise (Phrigian dominant) which, although containing a major third, is still very common in metal. So, if you learn these exercises you will be able to play six common ‘metal’ scales on six different strings and in six different keys.

EXERCISE 1

This lick is a descending sequence in ‘fours’ using E Natural minor (1-2-b3-4-5-b6-b7). Natural or ‘pure’ minor (also known modally as Aeolian) is the most common of the three basic minor scales (Natural, Harmonic, Melodic). For this exercise, use three fingers and a first finger shift-slide for each four-note grouping. Alternate picking is used throughout for a fast ‘shred’ sound.

Also in the ‘shred’ style, this is an ascending sequence frequently used by Yngwie Malmsteen. The scale used is A Harmonic minor (1-2-b3-4-5-b6-#7). For Harmonic minor, you play Natural minor but raise the seventh degree.

This is a relatively simple yet effective lick in C Dorian (1-2-b3-4-5-6-b7) involving two descending triplets climbing up the neck one note at a time. Think of Dorian as Natural minor but with a raised sixth.

Using D Phrigian (1-b2-b3-4-5-b6-b7), this lick descends via hammer-ons/pull-offs and slides in a three note sequence. Using hammer-ons /pull-offs is a great way to move around on one string. Phrigian is a Natural minor with a flattened second degree.

Instead of staying in the same position for two-handed tapping, this lick moves down the fretboard employing a fast double tap and slides. The scale used here is B Locrian (1-b2-b3-4-b5-b6-b7). Locrian is the seventh mode of the major scale and is akin to a Natural minor but with a flattened second and flattened fifth.

Although technically using two strings, Hendrix-style octaves can be very effective when played in a one-string manner, since the pattern of frets will stay the same even through you are using two strings. This lick takes things further by incorporating string skipping in the key of F# Phrigian dominant (1-b2-#3-4-5-b6-b7). Phrigian dominant can be though of as Natural minor with a flattened second and a raised third.